The fwip noise made by suppressed firearms in movies is among Hollywood's best lies. In truth, silencers are good to bring the report from about 140db to 110db: still pretty damned loud. In this video, Cameron Bryce overdubs a gunfight from John Wick which occurs in a crowded train station—the conceit being that silencers allow the exchange to happen surreptitiously— to add the sound of real suppressors.
If Bryce wanted to show how the scene would be impossible, though, I think he may have underestimated the ability of people to not notice things. The most interesting thing about the edited scene for me is that it becomes more convincing as a result. It seems well within the inattention envelope of the average commuter mob. It becomes a different kind of movie magic, a Verhoevenesque joke about bystander apathy. I remember kids setting off firecrackers on the Northern Line in the 90s and no-one batting an eyelid!